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/*
* Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
* Copyright (c) 2002-2006 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#include <sys/types.h>
#ifdef EVENT__HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef EVENT__HAVE_STDARG_H
#include <stdarg.h>
#endif
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#endif
#ifdef EVENT__HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef EVENT__HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef EVENT__HAVE_NETINET_IN6_H
#include <netinet/in6.h>
#endif
#include "event2/util.h"
#include "event2/bufferevent.h"
#include "event2/buffer.h"
#include "event2/bufferevent_struct.h"
#include "event2/bufferevent_compat.h"
#include "event2/event.h"
#include "log-internal.h"
#include "mm-internal.h"
#include "bufferevent-internal.h"
#include "util-internal.h"
#ifdef _WIN32
#include "iocp-internal.h"
#endif
/* prototypes */
static int be_socket_enable(struct bufferevent *, short);
static int be_socket_disable(struct bufferevent *, short);
static void be_socket_destruct(struct bufferevent *);
static int be_socket_adj_timeouts(struct bufferevent *);
static int be_socket_flush(struct bufferevent *, short, enum bufferevent_flush_mode);
static int be_socket_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
static void be_socket_setfd(struct bufferevent *, evutil_socket_t);
const struct bufferevent_ops bufferevent_ops_socket = {
"socket",
evutil_offsetof(struct bufferevent_private, bev),
be_socket_enable,
be_socket_disable,
be_socket_destruct,
be_socket_adj_timeouts,
be_socket_flush,
be_socket_ctrl,
};
#define be_socket_add(ev, t) \
bufferevent_add_event_((ev), (t))
static void
bufferevent_socket_outbuf_cb(struct evbuffer *buf,
const struct evbuffer_cb_info *cbinfo,
void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
if (cbinfo->n_added &&
(bufev->enabled & EV_WRITE) &&
!event_pending(&bufev->ev_write, EV_WRITE, NULL) &&
!bufev_p->write_suspended) {
/* Somebody added data to the buffer, and we would like to
* write, and we were not writing. So, start writing. */
if (be_socket_add(&bufev->ev_write, &bufev->timeout_write) == -1) {
/* Should we log this? */
}
}
}
static void
bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
struct evbuffer *input;
int res = 0;
short what = BEV_EVENT_READING;
ev_ssize_t howmuch = -1, readmax=-1;
bufferevent_incref_and_lock_(bufev);
if (event == EV_TIMEOUT) {
what |= BEV_EVENT_TIMEOUT;
goto error;
}
input = bufev->input;
/*
* If we have a high watermark configured then we don't want to
* read more data than would make us reach the watermark.
*/
if (bufev->wm_read.high != 0) {
howmuch = bufev->wm_read.high - evbuffer_get_length(input);
/* we somehow lowered the watermark, stop reading */
if (howmuch <= 0) {
bufferevent_wm_suspend_read(bufev);
goto done;
}
}
readmax = bufferevent_get_read_max_(bufev_p);
if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited"
* uglifies this code. XXXX */
howmuch = readmax;
if (bufev_p->read_suspended)
goto done;
evbuffer_unfreeze(input, 0);
res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */
evbuffer_freeze(input, 0);
if (res == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err))
goto reschedule;
/* error case */
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case */
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
bufferevent_decrement_read_buckets_(bufev_p, res);
/* Invoke the user callback - must always be called last */
if (evbuffer_get_length(input) >= bufev->wm_read.low)
bufferevent_run_readcb_(bufev);
goto done;
reschedule:
goto done;
error:
bufferevent_disable(bufev, EV_READ);
bufferevent_run_eventcb_(bufev, what);
done:
bufferevent_decref_and_unlock_(bufev);
}
static void
bufferevent_writecb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
int res = 0;
short what = BEV_EVENT_WRITING;
int connected = 0;
ev_ssize_t atmost = -1;
bufferevent_incref_and_lock_(bufev);
if (event == EV_TIMEOUT) {
what |= BEV_EVENT_TIMEOUT;
goto error;
}
if (bufev_p->connecting) {
int c = evutil_socket_finished_connecting_(fd);
/* we need to fake the error if the connection was refused
* immediately - usually connection to localhost on BSD */
if (bufev_p->connection_refused) {
bufev_p->connection_refused = 0;
c = -1;
}
if (c == 0)
goto done;
bufev_p->connecting = 0;
if (c < 0) {
event_del(&bufev->ev_write);
event_del(&bufev->ev_read);
bufferevent_run_eventcb_(bufev, BEV_EVENT_ERROR);
goto done;
} else {
connected = 1;
#ifdef _WIN32
if (BEV_IS_ASYNC(bufev)) {
event_del(&bufev->ev_write);
bufferevent_async_set_connected_(bufev);
bufferevent_run_eventcb_(bufev,
BEV_EVENT_CONNECTED);
goto done;
}
#endif
bufferevent_run_eventcb_(bufev,
BEV_EVENT_CONNECTED);
if (!(bufev->enabled & EV_WRITE) ||
bufev_p->write_suspended) {
event_del(&bufev->ev_write);
goto done;
}
}
}
atmost = bufferevent_get_write_max_(bufev_p);
if (bufev_p->write_suspended)
goto done;
if (evbuffer_get_length(bufev->output)) {
evbuffer_unfreeze(bufev->output, 1);
res = evbuffer_write_atmost(bufev->output, fd, atmost);
evbuffer_freeze(bufev->output, 1);
if (res == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err))
goto reschedule;
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case
XXXX Actually, a 0 on write doesn't indicate
an EOF. An ECONNRESET might be more typical.
*/
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
bufferevent_decrement_write_buckets_(bufev_p, res);
}
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
/*
* Invoke the user callback if our buffer is drained or below the
* low watermark.
*/
if ((res || !connected) &&
evbuffer_get_length(bufev->output) <= bufev->wm_write.low) {
bufferevent_run_writecb_(bufev);
}
goto done;
reschedule:
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
goto done;
error:
bufferevent_disable(bufev, EV_WRITE);
bufferevent_run_eventcb_(bufev, what);
done:
bufferevent_decref_and_unlock_(bufev);
}
struct bufferevent *
bufferevent_socket_new(struct event_base *base, evutil_socket_t fd,
int options)
{
struct bufferevent_private *bufev_p;
struct bufferevent *bufev;
#ifdef _WIN32
if (base && event_base_get_iocp_(base))
return bufferevent_async_new_(base, fd, options);
#endif
if ((bufev_p = mm_calloc(1, sizeof(struct bufferevent_private)))== NULL)
return NULL;
if (bufferevent_init_common_(bufev_p, base, &bufferevent_ops_socket,
options) < 0) {
mm_free(bufev_p);
return NULL;
}
bufev = &bufev_p->bev;
evbuffer_set_flags(bufev->output, EVBUFFER_FLAG_DRAINS_TO_FD);
event_assign(&bufev->ev_read, bufev->ev_base, fd,
EV_READ|EV_PERSIST, bufferevent_readcb, bufev);
event_assign(&bufev->ev_write, bufev->ev_base, fd,
EV_WRITE|EV_PERSIST, bufferevent_writecb, bufev);
evbuffer_add_cb(bufev->output, bufferevent_socket_outbuf_cb, bufev);
evbuffer_freeze(bufev->input, 0);
evbuffer_freeze(bufev->output, 1);
return bufev;
}
int
bufferevent_socket_connect(struct bufferevent *bev,
struct sockaddr *sa, int socklen)
{
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
evutil_socket_t fd;
int r = 0;
int result=-1;
int ownfd = 0;
bufferevent_incref_and_lock_(bev);
if (!bufev_p)
goto done;
fd = bufferevent_getfd(bev);
if (fd < 0) {
if (!sa)
goto done;
fd = evutil_socket_(sa->sa_family,
SOCK_STREAM|EVUTIL_SOCK_NONBLOCK, 0);
if (fd < 0)
goto done;
ownfd = 1;
}
if (sa) {
#ifdef _WIN32
if (bufferevent_async_can_connect_(bev)) {
bufferevent_setfd(bev, fd);
r = bufferevent_async_connect_(bev, fd, sa, socklen);
if (r < 0)
goto freesock;
bufev_p->connecting = 1;
result = 0;
goto done;
} else
#endif
r = evutil_socket_connect_(&fd, sa, socklen);
if (r < 0)
goto freesock;
}
#ifdef _WIN32
/* ConnectEx() isn't always around, even when IOCP is enabled.
* Here, we borrow the socket object's write handler to fall back
* on a non-blocking connect() when ConnectEx() is unavailable. */
if (BEV_IS_ASYNC(bev)) {
event_assign(&bev->ev_write, bev->ev_base, fd,
EV_WRITE|EV_PERSIST, bufferevent_writecb, bev);
}
#endif
bufferevent_setfd(bev, fd);
if (r == 0) {
if (! be_socket_enable(bev, EV_WRITE)) {
bufev_p->connecting = 1;
result = 0;
goto done;
}
} else if (r == 1) {
/* The connect succeeded already. How very BSD of it. */
result = 0;
bufev_p->connecting = 1;
event_active(&bev->ev_write, EV_WRITE, 1);
} else {
/* The connect failed already. How very BSD of it. */
bufev_p->connection_refused = 1;
bufev_p->connecting = 1;
result = 0;
event_active(&bev->ev_write, EV_WRITE, 1);
}
goto done;
freesock:
bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR);
if (ownfd)
evutil_closesocket(fd);
/* do something about the error? */
done:
bufferevent_decref_and_unlock_(bev);
return result;
}
static void
bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai,
void *arg)
{
struct bufferevent *bev = arg;
struct bufferevent_private *bev_p =
EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
int r;
BEV_LOCK(bev);
bufferevent_unsuspend_write_(bev, BEV_SUSPEND_LOOKUP);
bufferevent_unsuspend_read_(bev, BEV_SUSPEND_LOOKUP);
if (result != 0) {
bev_p->dns_error = result;
bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR);
bufferevent_decref_and_unlock_(bev);
if (ai)
evutil_freeaddrinfo(ai);
return;
}
/* XXX use the other addrinfos? */
/* XXX use this return value */
r = bufferevent_socket_connect(bev, ai->ai_addr, (int)ai->ai_addrlen);
(void)r;
bufferevent_decref_and_unlock_(bev);
evutil_freeaddrinfo(ai);
}
int
bufferevent_socket_connect_hostname(struct bufferevent *bev,
struct evdns_base *evdns_base, int family, const char *hostname, int port)
{
char portbuf[10];
struct evutil_addrinfo hint;
int err;
struct bufferevent_private *bev_p =
EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC)
return -1;
if (port < 1 || port > 65535)
return -1;
BEV_LOCK(bev);
bev_p->dns_error = 0;
BEV_UNLOCK(bev);
evutil_snprintf(portbuf, sizeof(portbuf), "%d", port);
memset(&hint, 0, sizeof(hint));
hint.ai_family = family;
hint.ai_protocol = IPPROTO_TCP;
hint.ai_socktype = SOCK_STREAM;
bufferevent_suspend_write_(bev, BEV_SUSPEND_LOOKUP);
bufferevent_suspend_read_(bev, BEV_SUSPEND_LOOKUP);
bufferevent_incref_(bev);
err = evutil_getaddrinfo_async_(evdns_base, hostname, portbuf,
&hint, bufferevent_connect_getaddrinfo_cb, bev);
if (err == 0) {
return 0;
} else {
bufferevent_unsuspend_write_(bev, BEV_SUSPEND_LOOKUP);
bufferevent_unsuspend_read_(bev, BEV_SUSPEND_LOOKUP);
return -1;
}
}
int
bufferevent_socket_get_dns_error(struct bufferevent *bev)
{
int rv;
struct bufferevent_private *bev_p =
EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
BEV_LOCK(bev);
rv = bev_p->dns_error;
BEV_LOCK(bev);
return rv;
}
/*
* Create a new buffered event object.
*
* The read callback is invoked whenever we read new data.
* The write callback is invoked whenever the output buffer is drained.
* The error callback is invoked on a write/read error or on EOF.
*
* Both read and write callbacks maybe NULL. The error callback is not
* allowed to be NULL and have to be provided always.
*/
struct bufferevent *
bufferevent_new(evutil_socket_t fd,
bufferevent_data_cb readcb, bufferevent_data_cb writecb,
bufferevent_event_cb eventcb, void *cbarg)
{
struct bufferevent *bufev;
if (!(bufev = bufferevent_socket_new(NULL, fd, 0)))
return NULL;
bufferevent_setcb(bufev, readcb, writecb, eventcb, cbarg);
return bufev;
}
static int
be_socket_enable(struct bufferevent *bufev, short event)
{
if (event & EV_READ) {
if (be_socket_add(&bufev->ev_read,&bufev->timeout_read) == -1)
return -1;
}
if (event & EV_WRITE) {
if (be_socket_add(&bufev->ev_write,&bufev->timeout_write) == -1)
return -1;
}
return 0;
}
static int
be_socket_disable(struct bufferevent *bufev, short event)
{
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
if (event & EV_READ) {
if (event_del(&bufev->ev_read) == -1)
return -1;
}
/* Don't actually disable the write if we are trying to connect. */
if ((event & EV_WRITE) && ! bufev_p->connecting) {
if (event_del(&bufev->ev_write) == -1)
return -1;
}
return 0;
}
static void
be_socket_destruct(struct bufferevent *bufev)
{
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
evutil_socket_t fd;
EVUTIL_ASSERT(bufev->be_ops == &bufferevent_ops_socket);
fd = event_get_fd(&bufev->ev_read);
event_del(&bufev->ev_read);
event_del(&bufev->ev_write);
if ((bufev_p->options & BEV_OPT_CLOSE_ON_FREE) && fd >= 0)
EVUTIL_CLOSESOCKET(fd);
}
static int
be_socket_adj_timeouts(struct bufferevent *bufev)
{
int r = 0;
if (event_pending(&bufev->ev_read, EV_READ, NULL))
if (be_socket_add(&bufev->ev_read, &bufev->timeout_read) < 0)
r = -1;
if (event_pending(&bufev->ev_write, EV_WRITE, NULL)) {
if (be_socket_add(&bufev->ev_write, &bufev->timeout_write) < 0)
r = -1;
}
return r;
}
static int
be_socket_flush(struct bufferevent *bev, short iotype,
enum bufferevent_flush_mode mode)
{
return 0;
}
static void
be_socket_setfd(struct bufferevent *bufev, evutil_socket_t fd)
{
BEV_LOCK(bufev);
EVUTIL_ASSERT(bufev->be_ops == &bufferevent_ops_socket);
event_del(&bufev->ev_read);
event_del(&bufev->ev_write);
event_assign(&bufev->ev_read, bufev->ev_base, fd,
EV_READ|EV_PERSIST, bufferevent_readcb, bufev);
event_assign(&bufev->ev_write, bufev->ev_base, fd,
EV_WRITE|EV_PERSIST, bufferevent_writecb, bufev);
if (fd >= 0)
bufferevent_enable(bufev, bufev->enabled);
BEV_UNLOCK(bufev);
}
/* XXXX Should non-socket bufferevents support this? */
int
bufferevent_priority_set(struct bufferevent *bufev, int priority)
{
int r = -1;
BEV_LOCK(bufev);
if (bufev->be_ops != &bufferevent_ops_socket)
goto done;
if (event_priority_set(&bufev->ev_read, priority) == -1)
goto done;
if (event_priority_set(&bufev->ev_write, priority) == -1)
goto done;
r = 0;
done:
BEV_UNLOCK(bufev);
return r;
}
/* XXXX Should non-socket bufferevents support this? */
int
bufferevent_base_set(struct event_base *base, struct bufferevent *bufev)
{
int res = -1;
BEV_LOCK(bufev);
if (bufev->be_ops != &bufferevent_ops_socket)
goto done;
bufev->ev_base = base;
res = event_base_set(base, &bufev->ev_read);
if (res == -1)
goto done;
res = event_base_set(base, &bufev->ev_write);
done:
BEV_UNLOCK(bufev);
return res;
}
static int
be_socket_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
union bufferevent_ctrl_data *data)
{
switch (op) {
case BEV_CTRL_SET_FD:
be_socket_setfd(bev, data->fd);
return 0;
case BEV_CTRL_GET_FD:
data->fd = event_get_fd(&bev->ev_read);
return 0;
case BEV_CTRL_GET_UNDERLYING:
case BEV_CTRL_CANCEL_ALL:
default:
return -1;
}
}
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